1. Field of the Invention
The present invention relates to a power saving method and device for a display device, and more particularly to a display device for controlling the brightness of a display unit based on a minimal brightness difference recognizable by a user, and a method of controlling the display device.
2. Description of the Related Art
A display device consumes power mostly for screen output. As image quality is improved and a screen size is increased, power consumption increases. When there is a great amount of central processing unit (CPU) operations or graphic processing and calculation operations, power consumption also increases. Use of a communication service also increases power consumption.
Recently, as portable display devices have been widely used, it is necessary to use various power saving modes in order to reduce power consumption of a display device. Unlike a typical fixed-type display device that is continuously supplied with power through a socket, a portable display device is limited in power, and thus an efficient power saving method is required.
To reduce power consumption of a portable display device, screen brightness is decreased, or an automatic screen lock function is performed to switch to a standby mode when there is no input from a user for a certain period of time. For instance, when the user selects a power saving mode, a screen may be kept dark according to the power saving mode. However, when the power saving mode is set, the user recognizes a change in a display state and thus may feel that it is unnatural.